Presentation to:

Robert T. MitchellCassini Program Manager

Jet Propulsion Laboratory, California Institute of Technology

February 10, 2011

Cassini Program

Project Management Challenge

Managing the Cassini Project’s Transition to Extended Mission

Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

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Cassini History

Launch on October 15, 1997, with ESA’s Huygens Probe

Seven year cruise to Saturn

Arrival and orbit insertion on July 1, 2004

Probe release on December 24

Descent through Titan’s atmosphere and probe data relay to Earth on January 14, 2005

Four-year prime mission orbital tour, 45 Titan encounters, 10 icy satellite encounters, 76 orbits

Twenty-seven month mission extension approved, 64 orbits, 28 Titan encounters, 8 Enceladus encounters, 3 with other smaller icy satellites

Equinox crossing in August, 2009

Seven-year second mission extension approved through September, 2017

155 orbits, 54 Titan encounters, 11 Enceladus encounters, 5 other icy moon encounters

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The Challenges – Top Level

Sell a second mission extension to NASA

Likely not to succeed at current budget

Define minimum “worthwhile” mission

Identify minimum funding level for reliable, worthwhile mission

Mission variables – tour complexity and observation design complexity

Challenges – Lower Level

Rein in science appetite

Six years of optimized sequences and adequate funding

Move to resource constrained sequences

Descope a solidly entrenched operations team

Design and build new tools and processes in parallel with full-up operations

Build and validate new ground system – H/W and S/W

Design seven year tour consistent with science objectives, available funding, and remaining consumables

Mission Summary

Mission Drivers

Frequent satellite encounters with three orbit trim maneuvers per encounter

Overlapping sequence development and execution activities

Six at a time in prime and Equinox missions

Distributed science operations over nine time zones

Twelve body-fixed instruments with conflicting pointing requirements

High Level Science Objectives

Study seasonal variations at Titan and Saturn

Investigate the Enceladus plumes

Increase mapping coverage of Titan’s surface

Determine the nature of Titan’s interior

Develop further understanding of the dynamics of Saturn’s rings

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Policies for Solstice Mission Operations

No change in position on risk to flight hardware

Modest increase in risk to science data return acceptable for cost reduction

No unreasonable workloads to be allowed

Prioritization of science activities required before sequencing

Limit initial sequence design to what can be implemented

Changes From Equinox and Prime Missions

Reduced overlapping sequence activities from six to three

Designed less complex tour (less frequent encounters, longer orbit periods)

Simpler observation sequences, less optimization and fine tuning

New guidelines and constraints on science sequence integration

Combined some functions to allow for more cross-training

Reduced DSN tracks from one per day to ~one every other day

Less optical navigation effort

Discipline focused periapses

Fewer meetings (telecons)

Reduced engineering support funding by 40%, science funding by 25%

XXM Sequence Implementation Process Transition

Why Did It Work?

Highly capable, experienced, and motivated team members

Ample lead time to do it right

Effective communications

Excellent systems engineering skills were available.

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